/*
 * Copyright (C) 2011 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.math;

import static com.google.common.math.MathBenchmarking.ARRAY_MASK;
import static com.google.common.math.MathBenchmarking.ARRAY_SIZE;
import static com.google.common.math.MathBenchmarking.randomNonZeroBigInteger;
import static com.google.common.math.MathBenchmarking.randomPositiveBigInteger;

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;

import java.math.BigInteger;
import java.math.RoundingMode;

/**
 * Benchmarks for the rounding methods of {@code BigIntegerMath}.
 *
 * @author Louis Wasserman
 */
public class BigIntegerMathRoundingBenchmark
{
    private static final BigInteger[] nonzero1 = new BigInteger[ARRAY_SIZE];
    private static final BigInteger[] nonzero2 = new BigInteger[ARRAY_SIZE];
    private static final BigInteger[] positive = new BigInteger[ARRAY_SIZE];

    @Param({"DOWN", "UP", "FLOOR", "CEILING", "HALF_EVEN", "HALF_UP", "HALF_DOWN"})
    RoundingMode mode;

    @BeforeExperiment
    void setUp()
    {
        for (int i = 0; i < ARRAY_SIZE; i++)
        {
            positive[i] = randomPositiveBigInteger(1024);
            nonzero1[i] = randomNonZeroBigInteger(1024);
            nonzero2[i] = randomNonZeroBigInteger(1024);
        }
    }

    @Benchmark
    int log2(int reps)
    {
        int tmp = 0;
        for (int i = 0; i < reps; i++)
        {
            int j = i & ARRAY_MASK;
            tmp += BigIntegerMath.log2(positive[j], mode);
        }
        return tmp;
    }

    @Benchmark
    int log10(int reps)
    {
        int tmp = 0;
        for (int i = 0; i < reps; i++)
        {
            int j = i & ARRAY_MASK;
            tmp += BigIntegerMath.log10(positive[j], mode);
        }
        return tmp;
    }

    @Benchmark
    int sqrt(int reps)
    {
        int tmp = 0;
        for (int i = 0; i < reps; i++)
        {
            int j = i & ARRAY_MASK;
            tmp += BigIntegerMath.sqrt(positive[j], mode).intValue();
        }
        return tmp;
    }

    @Benchmark
    int divide(int reps)
    {
        int tmp = 0;
        for (int i = 0; i < reps; i++)
        {
            int j = i & ARRAY_MASK;
            tmp += BigIntegerMath.divide(nonzero1[j], nonzero2[j], mode).intValue();
        }
        return tmp;
    }

    @Benchmark
    long roundToDouble(int reps)
    {
        long tmp = 0;
        for (int i = 0; i < reps; i++)
        {
            int j = i & ARRAY_MASK;
            tmp += Double.doubleToRawLongBits(BigIntegerMath.roundToDouble(nonzero1[j], mode));
        }
        return tmp;
    }
}
